If you want a career in accountancy you have a couple of options (that i can think of, im sure there are others).
1) Get a training contrat with an accountancy firm, there are literally hundreds out there, this is a list of the top 50 (by revenue i guess).
http://www.accountancyage.com/digital_assets/3322/AccyAgeTop50v6.pdf
These will train you to be a fully fledged ACA accountant, the big ones can be a bit snobby so I suggest finding a slightly smaller practise (the big ones want 2.1 at uni and decent A levels). The good thing is that they suck in hundreds of people into their training schemes every year. This will take up three years of your life but leave you VERY employable - I left PwC a month or so ago and am earning £55k in London.
2) The above option is fairly full on. You could decide to go to college to do an AAT course, this is basically an accounting technician course and will land you a role as a book keeper / junior accountant in industry (e.g. being an accountant for a company). You might find a firm that is will to sponsor you to do it otherwise pay for it yourself. I think there is some overlap with AAT and ACA so if you do AAT and like it I think you can skip some of the ACA exams.
You might find option number #1 to be tough, option #2 will be a bit more flexible.